Internationally, the exercise ECG is the most common initial test for the evaluation of stable chest pain and has been used widely for almost half a century.¹ In the UK, exercise ECGs are a routinely performed, central part of patient assessment in most chest pain clinics, the main site of initial specialist referral.²

The 2010 UK National Institute for Health and Clinical Excellence (NICE) guidelines recommend that exercise ECGs should no longer be used to diagnose or exclude stable angina in patients.^{3, 4} This recommendation is based on systematic reviews showing that other investigations have greater diagnostic accuracy^5–8 and may be more cost effective at detecting people who are subsequently found to have coronary artery disease.⁹ NICE recommends that the diagnosis of angina be based on clinical assessment alone or clinical assessment plus either anatomical imaging (eg, coronary angiogram) or functional testing (eg, stress echocardiography).

Medical technologies can have many functions beyond their explicit purpose.¹⁰ Although technologies can distance the clinician from the patient, in some clinical settings, they may facilitate a closer relationship.¹¹ Technologies, including diagnostic tests, are not neutral; they embody specific cultural values and a range of implicit and explicit functions.^12–14 Ethnographic¹⁵ and sociological¹⁶ investigation of medical diagnosis reveals that this is a complex and often problematic process, in which the clinician combines results of diagnostic tests with the patient's narrative (structured as a clinical history), implicitly or explicitly forming, weighing up and testing hypotheses.¹⁷ Clinical assessment and diagnosis takes place in specific settings in the context of a discursive and often physical relationship between clinician and patient. Guidance to clinicians needs to be informed by an understanding of this relationship and the clinical work of patient assessment, as well the diagnostic accuracy of symptoms, signs and tests.

Given the widespread use of the exercise ECG in assessments of patients with stable chest pain, this paper seeks to understand its role in the light of emerging evidence about its poor performance as a diagnostic test. This paper reports on the functions of the exercise ECG in UK chest pain clinics, highlighting those uses that go beyond its diagnostic function.

In two of the three clinics (A and B), all patients who were able to do so performed an exercise ECG supervised by the clinician who took their initial history. In clinic C, exercise ECGs were only requested for selected patients and supervised by cardiac technicians.

We have shown that in patients with new onset stable chest pain the exercise ECG has a role in articulating the clinical history through stimulating symptoms, such as chest pain and breathlessness, and prompting additional narrative details about their symptoms. For patients in whom angina is discounted, walking on the treadmill is used to reassure them that their symptoms are not cardiac in origin and that it is safe to exercise. Performing the exercise ECG gives patients an active physical role in the diagnostic process. During and after the exercise ECG, a context is provided within which the clinician can give specific advice on exercise, weight loss, diet and smoking cessation. If clinicians use the full potential of the exercise ECG, they may also draw on the patients' experience of walking on the treadmill to demonstrate appropriate levels of exercise and the amount of breathlessness they should be experiencing to improve their fitness. These specific benefits arise from exercising in front of the clinician and are not a function of the additional time spent with the patient.

Through the exercise ECG both patients and clinicians have the opportunity to become engaged experientially, transcending the test's diagnostic function, particularly when the clinician is present and able to supervise the test. This engagement is not usually present in functional tests for coronary artery disease that has better diagnostic accuracy, such as radioisotope scanning, stress ultrasound or MRI, because even when exercise is the stressor, the test is almost invariably removed in time and place from the clinic setting. Although some clinicians talked about the additional functions of the exercise ECG, many of these were implicit and emerged from our observations. Most of the clinicians we observed believed that the exercise ECG did contribute to their diagnostic decisions,²¹ and so it is ironic that just as we were observing the exercise ECG at the centre of demonstrating professional authority and expertise, the legitimacy of that tool was being removed by NICE. Most clinicians also recognised the prognostic value of the exercise ECG when asked directly in interview, but this was not reflected in our observations of their clinical practice.

In this ethnographic study of chest pain clinics, we have shown that the exercise ECG was being used for a range of clinical, psychosocial and educational purposes that potentially benefit patients. These benefits would be lost if the wider functions of the exercise ECG were not implemented through other means once the exercise ECG is phased out of the assessment of patients with new onset stable chest pain in line with the UK NICE chest pain guidelines. However, loss of its wider functions is not inevitable if a way is found to integrate the exercise stress used in more contemporary functional tests with the evaluation of the patient in the chest pain clinic.

Either with clinical assessment alone or assessment using other diagnostic technologies, patients may find themselves in a passive and physically static role in the absence of a supervising clinician. There will, for example, be no opportunities for patients to walk briskly on a treadmill stimulating symptoms and no opportunities for patients to use their experiences when walking to engage in a dialogue of questions and clarification. This will weaken the embodied^{22, 23} and performance aspect of chest pain diagnosis²⁴ that goes beyond verbal exchanges.¹⁶ The communication of pain is often difficult²⁵ and complicated by differences in gender²⁶ and ethnicity. Communicating chest pain is associated with additional anxieties.^{27, 28} As other studies have shown,²⁹ successful reassurance hinges on clinicians being able to indicate that they have understood a patient's current situation and can communicate this in the consultation. Our study suggests that through physical engagement the exercise ECG can facilitate communication between patient and clinician which, even if not improving diagnostic accuracy, does enhance subsequent reassurance.

Another important feature of exercise testing in two of the clinics we observed was the presence of the clinician making the assessment, often a senior nurse practitioner or staff grade cardiologist. This is not generally the case with other functional tests for angina which are conducted by a technician in a different space from the clinical assessment by a clinician. The splitting of a diagnostic test from the wider clinical assessment may affect the potential depth of the relationship³⁰ and the potential to clarify the clinical history through engagement with the test, particularly if this involves exercise.

As governments and professional bodies revise guidelines, the exercise ECG will have a diminishing role in the diagnosis of angina. However, many of the practices that have been built up around the use of the exercise ECG are potentially beneficial to patients and need to be considered in the re-design of chest pain assessment services without that test. In particular, the supervised exercising of patients, even if this does not explicitly inform diagnostic decisions or prognostic judgements, should form part of the assessment process.

To cite: Cramer H, Evans M, Featherstone K, et al. Treading carefully: a qualitative ethnographic study of the clinical, social and educational uses of exercise ECG in evaluating stable chest pain. BMJ Open 2012;2:e000508. doi:10.1136/bmjopen-2011-000508

Contributors: GF, HH and ADT designed the programme of research in which this study is embedded. GF and KF had the idea for the qualitative component of the study. HC and ME undertook the interviews, observations, analysed and interpreted the data, which were discussed with KF and GF. HC wrote the first draft. GF, KF, HH, MJSZ, ADT and RJ revised the article for important intellectual content. All members of the team gave final approval of the version published. GF and HC are the guarantors. All contributors had full access to all the data in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.

Funding:This work is supported by the National Institute for Health Research (NIHR) programme grant reference RP-PG-0407-10314 (NIHR, Room 132, Richmond House, 79 Whitehall, London SW1A 2NS, UK). The NIHR had no involvement in the research process or writing of this article.

Competing interests: All authors have completed the unified competing interest form at http://www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare (1) no financial support for the submitted work from anyone other than their employer, except ADT who previously had support from NICE for work on guideline development; (2) no financial relationships with commercial entities that might have an interest in the submitted work; (3) no spouses, partners or children with relationships with commercial entities that might have an interest in the submitted work and (4) no non-financial interests that may be relevant to the submitted work.

Patient consent: We used our own ethics approved consent form.

Ethical approval: The study was approved by the West London NHS multicentre research ethics committee (08/H0709/85).

Provenance and peer review: Not commissioned; externally peer reviewed.

Data sharing statement: There is no additional data available.

We thank all the patients and clinicians who gave their time and shared their experiences and opinions with us. We would especially like to thank Jenny Tagney for all her support and enthusiasm for this project.